Improved Power Coefficient of Horizontal Axis Wind Turbines Using Optimized Lift Control

2014 ◽  
Author(s):  
John A. Cooney ◽  
Theodore J. Williams ◽  
Thomas C. Corke
Keyword(s):  
Wind Turbines ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbines ◽  
Lift Control

Aerodynamic Design and Wind Tunnel Tests of Small-scale Horizontal-axis Wind Turbines for Low Tip Speed Ratio Applications

2022 ◽  
pp. 1-34
Author(s):  
Ojing Siram ◽  
Neha Kesharwani ◽  
Niranjan Sahoo ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Tunnel ◽  
Wind Turbines ◽  
Pitch Angle ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Small Scale ◽  
Wind Tunnel Tests ◽  
Tip Speed Ratio ◽  
Horizontal Axis Wind Turbines

Abstract In recent times, the application of small-scale horizontal axis wind turbines (SHAWTs) has drawn interest in certain areas where the energy demand is minimal. These turbines, operating mostly at low Reynolds number (Re) and low tip speed ratio (λ) applications, can be used as stand-alone systems. The present study aims at the design, development, and testing of a series of SHAWT models. On the basis of aerodynamic characteristics, four SHAWT models viz., M1, M2, M3, and M4 composed of E216, SG6043, NACA63415, and NACA0012 airfoils, respectively have been developed. Initially, the rotors are designed through blade element momentum theory (BEMT), and their power coefficient have been evaluated. Thence, the developed rotors are tested in a low-speed wind tunnel to find their rotational frequency, power and power coefficient at design and off-design conditions. From BEMT analysis, M1 shows a maximum power coefficient (Cpmax) of 0.37 at λ = 2.5. The subsequent wind tunnel tests on M1, M2, M3, and M4 at 9 m/s show the Cpmax values to be 0.34, 0.30, 0.28, and 0.156, respectively. Thus, from the experiments, the M1 rotor is found to be favourable than the other three rotors, and its Cpmax value is found to be about 92% of BEMT prediction. Further, the effect of pitch angle (θp) on Cp of the model rotors is also examined, where M1 is found to produce a satisfactory performance within ±5° from the design pitch angle (θp, design).

scholarly journals The Yawing Behavior of Horizontal-Axis Wind Turbines: A Numerical and Experimental Analysis

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 15 ◽  
Author(s):  
Francesco Castellani ◽  
Davide Astolfi ◽  
Francesco Natili ◽  
Francesco Mari
Keyword(s):  
Wind Tunnel ◽  
Wind Turbines ◽  
Experimental Analysis ◽  
Numerical Models ◽  
Dynamical Behavior ◽  
Simulation Software ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Thrust Coefficient ◽  
Horizontal Axis Wind Turbines

The yawing of horizontal-axis wind turbines (HAWT) is a major topic in the comprehension of the dynamical behavior of these kinds of devices. It is important for the study of mechanical loads to which wind turbines are subjected and it is important for the optimization of wind farms because the yaw active control can steer the wakes between nearby wind turbines. On these grounds, this work is devoted to the numerical and experimental analysis of the yawing behavior of a HAWT. The experimental tests have been performed at the wind tunnel of the University of Perugia on a three-bladed small HAWT prototype, having two meters of rotor diameter. Two numerical set ups have been selected: a proprietary code based on the Blade Element Momentum theory (BEM) and the aeroelastic simulation software FAST, developed at the National Renewable Energy Laboratory (NREL) in Golden, CO, USA. The behavior of the test wind turbine up to ± 45 ∘ of yaw offset is studied. The performances (power coefficient C P ) and the mechanical behavior (thrust coefficient C T ) are studied and the predictions of the numerical models are compared against the wind tunnel measurements. The results for C T inspire a subsequent study: its behavior as a function of the azimuth angle is studied and the periodic component equal to the blade passing frequency 3P is observed. The fluctuation intensity decreases with the yaw angle because the distance between tower and blade increases. Consequently, the tower interference is studied through the comparison of measurements and simulations as regards the fore-aft vibration spectrum and the force on top of the tower.

A torque matched aerodynamic performance analysis method for the horizontal axis wind turbines

Wind Energy ◽  
2013 ◽  
Vol 17 (11) ◽  
pp. 1727-1736 ◽  
Author(s):  
Ali Al-Abadi ◽  
Özgür Ertunç ◽  
Horst Weber ◽  
Antonio Delgado
Keyword(s):  
Performance Analysis ◽  
Wind Turbines ◽  
Aerodynamic Performance ◽  
Horizontal Axis ◽  
Analysis Method ◽  
Horizontal Axis Wind Turbines
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